Adjustable leg extension for towers



Oct. 23, 1928.

I. w. MARSHALL ADJUSTABLE LEG EXTENSION FOR TOWERS Filed Jan. 17, 1925 INVENTOR Patented Oct. 23, 1928.

UNITED STATES IRA W. MARSHAIL, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 BLAW-KNOX COMPANY, OF PITTSBURGH, PENNSYLVANIA, A ooRPoRA'rIoN on NEW JERSEY.

ADJUSTABLE LEG nxrrnnsion Eon 'rownns.

Application filed January 17, 1925, Serial no. 3,067.

The present invention relates to structural towers, suchas are employed for carrying erected on hillsides where the cost of bring ing all four leg foundationstothe same height is excessive. By the present invention, I have provided an adjustable extension adapted to be applied to one or more legs of a tower for connecting such legs to the corresponding leg foundations. This leaves it optional with the person making the installationof a hillside tower as to the pre cise elevation of the tops of the leg foundations, and enables the tower to be erected from standard structural parts, and thus obviates the necessity of having a special design for hillside towers or of going to the great expense in building footings for these towers at elevations considerably above the ground level.

The accompanying sheet of drawings shows in side elevation the lower part of a tower having adjustable leg extensions embodying my invention connecting two of the legs of the tower with the corresponding leg foundations, which, as shown, are in the form of earth anchors.

Referring to the drawings, 2'and 3 represent two of the corner angles or legs of a transmission tower, whichwill be assumed to be a rectangular tower having the corner angles constituting the legs 90? angles, but which might be, so far as the present invention is concerned, a triangular tower, in which case the corner angles would be angles. The earth anchors, as shown, consist of studs 4 and 5 embedded in concrete foundations 6 and 7 which extend to substantially the same depth below the ground line 8, the latter representing a hillside. The upper ends of the studs are at substantially the same height above the ground line, and therefore at different distances below a horizontal plane such as indicated by the chain lines 9 and 10.

I will now describe the adjustable leg extension which constitutes the present invention. Angles 11 and 12 constitute extension members which fit into the corner angles 2 and 3 and may be slid up and down therein so as to bring their lower end portions at suitable levels for connection with the upper end portions of the studs4 and 5 to which they are 'secured by bolts at the holes 13. I

The upper end portion of the member 11 is bolted to the lower end portion of the tower leg 2 at the holes 14. The member 11 also has other holes 16, 17,18, 19 and '20, etc, by means of whiclrit'may be boltedto the leg 2 in different positions of extension. The

stud4 willbe set ata proper elevation for using one of the above sets of holes. The

member 12 will be similarly connected to the.

leg 3and stud 5.

7 An angle member 21 extends across betweenthe legs'2 and 3 and is connected at its opposite ends to the lower ends of saidlegs.

A diagonal bracing angle member 22 is bolted at one end at the hole 23 to the member 11, thus providing a pivotal connection between the end of the diagonal bracing member and the member 11, so that when the member 11 is connected to the leg 2 in different positions of extension, the member 22 can be swung aroundin the different positions indicated by the chain lines a, b, c, d and e, etc. In these different positions of the diagonal member 22, its upper end portion is bolted to'the member 21 through the holes 24, 25, 26, 27

and 28 in diagonal member 22, and the holes 'maybe bolted to the leg 2 and member 11 at the bolt hole 44, and the member 11 may be additionally secured to the leg 2 by bolts at the bolt holes 45. Additional groups of bolt holes 46, 47, 48, 49 and 50, corresponding to the holes 44 and 45, may be provided for the different positions of the member 11. The members 21 and 35 may be similarly secured to the leg 3 and member 12.

A diagonal bracing angle member 51 is bolted to the member 12 and to'the members 34, 35and 36 and serves to brace the member 12. The member 51 can assume different positions corersponding to the positions a, b, 0, etc. of the member 22, and can be adjustahly bolted to the members 34, 35 and 36 through the bolt holes 52, 53, 54, etc. 1 The member 51 does not extend to and-connect fivith mem her 21, because It is desirable to use structural steel angles for the members 34, 51, etc. and

it would not be feasible to fasten the member 51 adjustably to the member 21 injthe, same manner as the member 22, because the flanges of the angles Would prevent such connection.

If'eaeh of the four legs of a tower is to have an adjustable extension member secured thereto, the bracing arrangement shown may be applied-to all four sides of the tower and will providettlre properfbrac'ing in both directions'to hold the legs firmly in place; T his bracing arrangement Mali-we've; be applied to only one of the tower legs. For ex"- ainpl'e, the extension member 19' and the diag onal' bracing'member 51 may beflomitted altogether, and the stud'5 secured directly to the leg 3, this being the usual manner of connecnon; In'that case,' the bracing arrangement shown would be applied to eachofthe two sides of the towerinter'seeting'iat the leg 2' so as to provide for bracing the 2"1'11 two directionst p 5 .I/Vhile I have shown a preferred embodime'nt of my invention, it will be understood that the invention is not limited to the exactdetails of construction, or to the exa'cta'rand connected to each, a diagonally e'xten'dii'ig bracing element Connected to'said leg exten sion at one of its ends and having" itsoth'er end connected with a cross gift between the two legs, a' vertical member on' the cross 'gi'rt, diagg'o'n'als eXt'e'ndmg from each leg adJaCent the cross gift-to the vertical member, and an other diagonal connected with the outer 19g and with the said'yerticalmember.

In testimonyuvhereof I have hereuntoset my hand. i a

' IRA WL MARSH LL.- 

